Float switch, a control apparatus and a warning apparatus of an engine

Abstract

A float switch and a control apparatus of an internal combustion engine are disclosed. This float switch comprises a float attached to a main body so as to be vertically swung around one end thereof, a magnetic material fixed to the float, and a contact adapted to be closed or opened in response to the approach or removal of the magnetic material. The float switch is provided in the pathway of a collant passage and a lubricating oil passage of the engine. The control apparatus has a warning apparatus which is operative in response to an absence signal from the float switch which is indicative of the absence of the fluid that is being sensed, and has a rotating speed control apparatus to reduce the engine speed. The absence of the fluid is informed to the operator by the warning and the speed reduction. A warning apparatus for an outboard engine to control the engine speed when an abnormality occurs is also provided. This apparatus comprises a rotating speed detecting circuit, a circuit to set the engine rotating speed in correspondence to the abnormality, and a circuit to suppress the engine speed when the detected speed exceeds a preset value. The rotating speed is also reduced when coolant is not sufficiently supplied into the water jacket or when the engine lacks oil.

What is claimed is: 
     
       1. A switch for sensing fluid flow therepast in a first direction, comprising: a main body having thereon an outward projection which extends generally transverse to said first direction; a reed switch provided on said projection; and a member having a magnet thereon and supported on said main body for movement between first and second positions in which said magnet is respectively adjacent and spaced from said reed switch, said reed switch being actuated by the magnetic field of said magnet when said magnet is in said position adjacent said reed switch, said member including a portion having thereon a substantially flat surface which faces in a second direction substantially opposite said first direction, said portion moving approximately in said first direction as said member moves away from said first position thereof; wherein said member is supported at one end on said main body for pivotal movement about a pivot axis which extends in a direction transverse to the direction in which said projection projects outwardly from said main body and transverse to said first direction; wherein said portion of said member is an enlarged end portion at an end thereof remote from said pivot axis; wherein said projection has a convex surface thereon which faces said member and said member has in said substantially flat surface a groove containing a concave surface which faces said projection; wherein in said first and second positions said concave and convex surfaces are respectively adjacent and spaced from each other; wherein in said adjacent position of said convex and concave surfaces said magnet and said reed switch are in said adjacent position and said enlarged end portion of said member projects outwardly past an outer end of said outward projection; and wherein said magnet is partially embedded in said member but has a portion which projects outwardly from said concave surface into said groove. 
     
     
       2. The switch according to claim 1, wherein said main body includes an attaching portion having thereon a cylindrical and radially outwardly facing surface, said cylindrical surface having therein an annular groove, and including an O-ring disposed in said annular groove. 
     
     
       3. The switch according to claim 1, wherein said main body and said projection thereon are integral portions of a single structural element made of a nonmagnetic material. 
     
     
       4. The switch according to claim 1, wherein said pivot axis extends substantially parallel to said substantially flat surface, and wherein said substantially flat surface extends the full width of said portion of said member in a direction parallel to said axis. 
     
     
       5. The switch according to claim 1, wherein said substantially flat surface and said groove therein each extend to an end of said member remote from said axis.